The present invention relates to a method for dynamic control of an object along a path.
In particular, the present invention relates to a method of imparting a given law of motion to an object traveling along a path.
The present invention may be used to advantage on continuous packing machines, to which the following description refers purely by way of example.
To feed articles along a wrapping path, certain known continuous packing machines (for example of the type disclosed in EP-A1-496046) employ a conveyor having a series of carriages (or trains of carriages) fed along a fixed guide by an actuating device. Along one or more portions of the path, each carriage must be fed according to a given law of motion to time the carriage with respect to, and enable the carriage to cooperate with, other movable members along the path, and so prevent improper timing resulting in damage to the packing machine.
On known packing machines of the type described above, each carriage is timed along a portion of the path by engaging the carriage mechanically by means of a locating member, which advances according to the desired law of motion and normally engages a seat formed in the bottom of the carriage. This solution poses several drawbacks by the locating members engaging and releasing the respective seats cyclically, thus resulting, especially during engagement, in a relatively high noise level caused by the impact of each locating member against the walls of the respective seat, and, above all, in severe wear of the locating member-seat connection.
EP-A2-276409 or US-A1-5476035 discloses a magnetic conveyor having a plurality of carriages, each of which is fed along a given path by connecting such carriage to a traveling body using a magnetic field generated by the body or the carriage. The magnetic conveyors disclosed in both EP-A2-276409 and US-A1-5476035 may be advantageously used for feeding a carriage along a linear path with a relatively low speed and precision in position, but are not able to give the relatively high performances of conveyance (i.e. high speed and/or high precision in position) requested by a timing device of a modern packaging machine.
It is an object of the present invention to provide a method for dynamic control of an object along a path, designed to eliminate the aforementioned drawbacks, and which, in particular, is straightforward and cheap to implement.
According to the present invention, there is provided a method for dynamic control of an object along a path as recited in claim 1.
The present invention also relates to a device for timing an object along a path.
According to the present invention, there is also provided a device for dynamic control of an object along a path as recited in claim 6.